Rationale and objectives Theory suggests that tacit clues inform clinical judgements, but the prevalence and role of tacit clues during clinical interactions is unknown. This study explored whether doctors and patients identify information likely to be tacit clues or judgements based on tacit clues during health maintenance examinations. Methods Qualitative analysis of video elicitation interview transcripts involving 18 community-based primary care doctors and 36 patients. Outcomes were description and analysis of tacit clues and judgements based on tacit clues mentioned by participants. Results A total of 57 references to tacit clues and 53 references to judgements based on tacit clues were identified from patient and doctor transcripts. Non-verbal behaviours comprised the most common category of tacit clues (53% of doctor comments; 42% of patient comments). Patients mostly discussed judgements based on tacit clues that related to the doctor-patient relationship. Doctors discussed actively using non-verbal behaviours to provide patients with tacit clues about the doctor-patient relationship. They also mentioned tacit clues that informed medical judgements and decision making. Gestalt judgements based on tacit clues were common (33% of doctor comments). Several participants identified instances in which they had difficulty articulating their rationale for specific judgements. Doctors varied widely in how frequently they mentioned tacit clues. Conclusion During video elicitation interviews, patients and doctors identified tacit clues and judgements based on these clues as playing a role during health maintenance examinations. Future research should further elucidate the role of tacit clues in medical judgements and doctor-patient relationships.